A window treatment may be mounted in front of an opening, such as a window, for example, to prevent sunlight from entering a space and/or to provide privacy. Window treatments may include, for example: roller shades, roman shades, venetian blinds, or draperies. A roller shade typically includes a flexible shade fabric wound onto an elongated roller tube.
A window treatment may be motorized. For example, a motorized roller shade may include a motor drive unit that is coupled to the roller tube to provide for tube rotation. When operated, the motor drive unit may cause the roller tube to rotate, such that the shade fabric is raised or lowered along a vertical direction, for example.
Motorized window treatments are often installed in residential applications. For example, motorized roller shades may be installed in front of one or more windows in a home. However, motorized window treatments may also be installed in larger scale applications. For example, large scale motorized roller shades may be installed in commercial spaces.
FIG. 1 depicts an example of a prior art overhead installation of a motorized window treatment 100 (e.g., a motorized roller shade) in an interior space of a commercial building, for instance a lobby or an atrium space. The motorized window treatment 100 includes a roller shade assembly 102. The roller shade assembly 102 includes a covering material (e.g., a shade fabric 104) that may be raised and lowered to cover an opening (e.g., windows 106), for example. The roller shade assembly 102 further includes a roller tube (not shown), to which an upper end of the shade fabric 104 is attached. The roller tube may be driven by an electric motor drive unit (not shown) to raise and lower the shade fabric 104. The roller shade assembly 102 further includes a hembar 108 that is attached to a lower end of the shade fabric 104. The hembar 108 may be weighted, such that the hembar 108 causes the shade fabric 104 to hang (e.g., vertically) in front of the windows 106.
In an overhead installation, a motorized roller shade may be attached to one or more structural elements of a building, such as an I-beam or other structural element. As shown, the roller shade assembly 102 is supported by opposed end brackets 110 that are attached to the ceiling or wall of the building, such that the motorized window treatment 100 is attached to the ceiling or wall of the building in a mounted position.
If the roller shade assembly 102 becomes inadvertently detached from the mounted position, the roller shade assembly 102 may fall. It is thus desirable to ensure that, if the roller shade assembly becomes inadvertently detached from its mounted position, the roller shade assembly is prevented from falling in an uncontrolled manner.